Templates

Templates are used to format input messages before sending them to the action. For example - before sending a message to Microsoft Teams there is a need to format the input JSON into an HTML. This is done using a template.

Each template has a name field, which is used by the route to assign the template to input and output.

Tip

Use the default Legacy template "html" for general output

settings

In addition to name, a template will have one of the 4 below keys:

Key	Description	Example
rego-package	Postee loads bundle of templates from `rego-templates` folder. This folder includes several templates shipped with Postee, which can be used out of the box. You can add additional custom templates by placing Rego file under the 'rego-templates' directory.	`postee.vuls.html`
body	Specify inline template. Relative small templates can be added to config directly	input
url	Load from url. Rego template can be loaded from url.	http://myserver.com/rego.txt
legacy-scan-renderer	Legacy templates are introduced to support Postee V1 renderers. Available values are "jira", "slack", "html". "jira" should be used for jira integration, "slack" is for slack and "html" is for everything else.	html

Tip

Pre made examples for templates can be found here

Customizing Templates¶

It is possible to customize templates and even write new ones from scratch. Follow the guide in our advanced section here: Customizing Templates

Troubleshooting of Rego Templates¶

Rego templates provide very flexible way for transformation of received json. You can convert received information to html or json. On the flip side sometimes it may be difficult to find root cause of issue (if you run into any while configuring custom template). Postee application doesn't have many options to provide detailed error message. Very often if something goes wrong then 'result' property is omitted from rego evaluation result and it causes errors like:

2021/07/23 18:27:31 Error while evaluating input: property result is not found

So here are details to help with troubleshooting:

Required tools¶

opa - tool to evaluate OPA queries directly
jq - flexible command-line JSON processor.

Evaluate template to build html¶

Here is example of command to evaluate rego:

opa eval data.postee.vuls.html.result --data vuls-html.rego --data common/common.rego --input <path to input json> | jq -r .result[0].expressions[0].value

The example above should be started in rego-templates folder and evaluates default html template shipped with postee. First opa argument is query. Three parts are used to build query data.<your rego package>.result. You may want to evaluate title property. In this case query would be: data.<your rego package>.title

Evaluate template to build json¶

cd rego-templates
opa eval data.postee.vuls.slack.result --data vuls-slack.rego --data common/common.rego --input <path to input json> | jq .result[0].expressions[0].value

The command above is similar to html case but jq is used a bit different way.